He competed in the Mr Universe contest alongside lifelong friend Arnold Schwarzenegger and trained Christopher Reeve for his role as Superman.

His huge frame got him the role as the man behind the Darth Vader mask in the first three Star Wars films, after he turned down the original offer to play Han Solo’s hairy co-pilot Chewbacca, a 200-year-old Wookiee,

Bristol born Dave’s voice was dubbed over, a shock to him until he saw the first film, by James Earl-Jones.

He went on to appear in many other films, including A Clockwork Orange, but says his greatest job was as the Green Cross Code man during the 1970s. Annual child road injuries and deaths in Great Britain were halved to 20,000 and he got the MBE.

He told The Star: “The kids knew the Green Cross Code Man was Darth Vader. It had such a beneficial effect.”

Dave is attending the first Sheffield Film and Comic Convention both days, with his autograph and phto shoot cost £15. Photo shoot will be added for both days. Times will be confirmed at the show.

Film and TV fans can browse hundreds of stalls selling collectable movie merchandise, costumes and toys. There will be a large number of free guest talks and several paid for premium guest talks over the weekend.

Autograph hunters can also meet Buffy star Anthony Head and 1980s TV legend Dirk Benedict, from The A-Team and Battlestar Galactica, who are amongs the VIP signers. The A-Team van and Michael Knight’s Kitt car from Knight Rider, will also be making an appearance.

Darth Vader star Dave Prowse was also the Green Cross Code Man

Doctor Who fans can have their photo with former Time Lord Paul McGann and his Tardis.

Sylvester McCoy, the seventh Doctor, who preceded McGann, will be there with others, past and present from the cult series, currently enjoying a new Saturday night BBC TV return, including Louise Jameson, Bonnie Langford, Sophie Aldred, Mat Irvine, John Leeson, Terry Molloy, Dan Starkey and Frazer Hines, plus Eve Myles and Burn Gorman, from Doctor Who spin off TV series Torchwood.

Virginia Hey from Farscape and Mad Max 2, Craig Charles and Chris Barrie from Red Dwarf, plus Jeremy Bulloch, Ian Liston, John Morton, Jack McKenzie and Paul Blake from Star Wars are also coming, along with many other stars.

* Sheffield Film and Comic Convention will run Saturday and Sunday, August 30 and 31, 2014, early bird entry from 9am, standard entry 11am, until 6pm.

Tickets £3.30 to £16.50, including booking fees. Buy in person from the Arena Box Office, call 0114 256 5656 or buy online, where you will find latest details and any guest additions and amends, at www.motorpointarenasheffield.co.uk.